Field
The present invention relates to a fuel cell and to a fuel cell system.
Related Art
Fuel cells have been known that include end plates on both sides of a stacked body formed by stacking a plurality of unit cells. A configuration of such a fuel cell has been proposed in which the stacked body is accomodated in a fuel cell case avid one of the end plates, closing an opening portion, is fixed to the fuel cell case with a bolt (JP2013-228192A).
In the fuel cell having a stacked structure obtained by stacking the unit cells, a compressive load is applied in a stacking direction to maintain the stacked state and a favorable contact state among the unit cells. In the structure in which the end plate is fixed to the fuel cell case with the bolt as described above, a bolt with a small shaft diameter (nominal diameter) has conventionally been employed to achieve high apace efficiency. The compressive load, applied to the stacked body, is maintained by the bolt hastening the end plate to the fuel cell case. Thus, when the bolt with a small shaft diameter is used, a shaft of the bolt might be extended by reaction against the compressive load (plastic deformation). When the shat of the bolt is extended, a gap might be formed between the end plate and the fuel cell case, and thus the compression state of the stacked body might fail to be favorably maintained. As a result, the compressive load applied to the stacked body might be reduced. Thus, a technique has been called for that prevents the reduction of the compressive load applied to the stacked body, in the fuel cell having the stacked structure obtained by stacking a plurality of unit cells.